The effects of Panax ginseng water extract on spatial working memory disruption induced by scopolamine were examined using a T-maze delayed alternation task in rats. Scopolamine (0.025–0.1 mg/kg, i.p.) dose-dependently impaired the maze performance, and physostigmine (0.4 mg/kg) significantly reversed the scopolamine (0.1 mg/kg)-induced performance deficits. Ginseng extract (0.5–4.0 g dried root/kg) orally administered 60 min before testing dose-dependently improved the maze performance disrupted by scopolamine (0.1 mg/kg). Ginseng extract given for 7 days in drinking water (2.0 and 4.0 g/kg/day) also exhibited dose-dependent reversal of the scopolamine-induced performance deficits. These data indicate the beneficial effects of ginseng extract on spatial working memory in rats.